This project will exploit the recent development of rigid, vertically aligned, carbon nanofiber arrays to provide nanoscale probes for mapping intra and extracellular molecular events in and around living cells in real time with extremely high spatial resolution (< 50 nm probing areas). Devices will be fabricated and characterized to determine the performance of nanoscale arrays as independently addressable electrochemical molecular probes. Characterizations will be performed using a set of standard analytes that have been routinely used for characterization of carbon-based electrode systems (year 1). Probe response to hydrogen peroxide and superoxide anion will then be characterized (year 1 into year 2). Strategies and methods will then be develop for coupling nanofiber arrays around individual and groups of living cells (year 2). Electrochemical analysis techniques will be applied at individual elements of carbon nanofiber arrays to spatially and temporally map the activity of peroxide around and ultimately within individual cell locales (year 3). This research will be structured around development of these methodologies using microfluidic-based cell and analyte handling strategies, thereby promoting future high-throughput screening applications, such as clinical diagnostics of cell and tissue specimens and pharmaceutical exploration and discovery. This effort will be conducted by various organizational groups within the Oak Ridge National Laboratory. The Interdisciplinary team involved with this effort features mechanical and electrical engineers with experience in microfluide systems/semiconductor/and nanoscale fabrication, a biochemist and biologist with expertise in cell culture and single cell monitoring, analytical chemists, and a biophysicist, with expertise in cell signaling and environmental response. This effort will directly address BRP thrust areas including nanotechnology and microtechnology, functional genomics/microarray technology/gene expression analysis, cell and molecular imaging, and complex biological systems.